mux:github.com/gorilla/mux
func RegisterWebRoutes(r *mux.Router) {
.
.
.
// 静态资源
r.PathPrefix("/css/").Handler(http.FileServer(http.Dir("./public")))
r.PathPrefix("/js/").Handler(http.FileServer(http.Dir("./public")))
// 中间件:强制内容类型为 HTML
r.Use(middlewares.ForceHTML)
}